Scientific Papers Series A. Agronomy

The following presents several technological
issues resulted from the three years of
experimentation.
Thus, deep ploughing in autumn was followed
by two disking in spring and complex
fertilization in doses of 80kg/haN and
30kg/haP. Seeding was conducted at the
beginning of May, using the maize hybrid LG
3330 at a density of 5.5pl/m 2 . Weed sampling
was performed in three phenophases, as
follows:
- 20 days after emergence (20 ZDR);
- 40 days after emergence (40 ZDR);
- 60 days after emergence (60 ZDR).
Numerical and gravimetric analysis was
performed on the space between the rows and
on the rows, results being related to one linear
metre (1m).
On-row analysis included 6 cm on both sides of
the row, over a 1m distance. The six
centimetres represent the plant protection area
during mechanical hoeing.
The analysis on the space between rows
included a distance of 58 cm, i.e. 70 cm (the
technological distance between the rows) minus
the protection area (6 cm on each side of the
row), over a 1m distance.
Table 1. Experimental variants analyzed during the experiments carried out at SCDA Caracal
Mechanical-ZDR days
Manual-ZDR days
No. var Treatments
20 40 60 20 40 60
1. 2Mec (I,II) Control yes yes
2. 2man (I,II) yes yes
3. 2Mec (I,II) +1man (II) yes yes yes
4. 1Mec (II) +2man (I,II) yes yes yes
5. 2Mec (I,II) +1man (I) yes yes yes
6. 1Mec (I) +2man (I,II) yes yes yes
7. 2Mec (1,2) +2man (1,2) yes yes yes yes
8. 2Mec (I,II) +2man (I,II) yes yes yes yes
9. 3Mec +2man (I,II) yes yes yes yes yes
10. 3Mec +3man (1,2,3) yes yes yes yes yes yes
11. 3Mec + 3 man (I,II,III) yes yes yes yes yes yes
RESULTS AND DISCUSSIONS
The research performed at SCDA Caracal
between 2009 and 2011 resulted in a wide
range of resultson the influence of the manual
and mechanical hoeing on weeding in the
maize crop, partly presented in this paper.
1. Weed evolution on maize row depending
on the mechanical and manual works
applied.
The analysis of the data presented in Table 2
shows the evolution of weed density on the
maize rows, prior to the three hoeing epochs
(20 ZDR, 40 ZDR si 60 ZDR).
At 20 ZDR (days after emergence), the weed
number varied between 19.9 plt./ml in variant
V 7 -2Mec (1,2) +2 man (1,2) and 25.2 in V 9 -
3Mec (I, II, III) +2 man (I, II), while the control
2 Mec I, II recorded 22.8 plt./m. Compared
with the control, there were no significant
differences between the experimental variants.
Before the second-epoch works (40 ZDR), the
degree of weed infestation on the maize row
ranged between 7.1 plt./ml in V 11 -2Mec + 3
man (I, II, III) and 21.9 plt./ml la V 3 -2Mec
(I,II) +1 man (II). Except for variant V 3 , all
other variants showed a decrease in the degree
of infestation, compared with the control.
At 60 ZDR, the weed number decreased to 4.8
plt./m in V 11 -3Mec+3 man (I, II, III), recording
significant differences for all combinations of
mechanical and manual hoeing, compared with
the control.
The analysis of the weed number as the mean
for the three epochs of observation also showed
the favourable effect of combining mechanical
with manual works, the degree of infestation
ranging between 49% and 76%, compared with
the control.
For the mean values, it should be noted that
weeding had a certain dynamics. The mean
values included the dynamics, particularly due
to reinfestation which is a natural phenomenon,
given the biological characteristics of the plant
species.
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